Designation: Pickerings Triangle. The Veil Nebula is a cloud of heated and ionized gas and dust in the constellation Cygnus. It constitutes the visible portions of the Cygnus Loop (radio source W78, or Sharpless 103), a large but relatively faint supernova remnant. Pickering's Triangle (or Pickering's Triangular Wisp), is brightest at the north central edge of the loop, but visible in photographs continuing toward the central area of the loop. (Wiki)